Platen printing press



June 11, 1935. R. JOHNSON PLATEN PRINTING PRESS 2 Sheets-Sheet 1 I Filed April 11, 1954 INVENTOR. ZaW/e/gae 7F Jo%/1:0/z

ATTORNEY June 11, R JOHNSON PLATEN PRINTING PRESS Filed April 11, 1954 2 Sheets-Sheet 2 INVENTOR.

Patented June 11, 1935 PLATEN rnm'rmo PRESS Lawrence R. Johnson, Cleveland, Ohio, assignor .to The Chandler& Price-Company, Cleveland, Ohio, a corporation of Ohio Application April 11, 1934, Serial No. 720,083

Claims.

This invention relates as indicated to platen printing presses, but has reference more particularly to the platen grippers of such presses and to the means for controlling the movement of such grippers.

In printing presses of the Gordon .or platen type, the. platen is usually supportedfor oscillatory movement which must 'be imparted thereto in order tobring a sheet thereon in contact with the form. The platen is usually provided with two or more grippers which are monntedxon a gripper :bar that is pivotally attached at its re- .spective ends to the lower edge of the platen. Incidentally to oscillation of the platen, the gripper bar is oscillated so as to swing the grippers .carried thereby downwardly against the face of the platen, the function of the grippers being to retain the sheet in place-during the printing operation. To accommodate the grippers to sheets of various sizes;-'they are preferably adjustably mounted on the gripper bar, being secured in desired location by means of suitable xclampnuts. ,1

The platen oscillates-between a substantially horizontal sheet-receiving position'aand a substantially vertical form-engaging or sheetprinting position, and the operation of the grippers which is synchronized with that of the platenhas heretofore been .so=timed ,as to cause the grippers to recede from the face of the platen immediately afxterthe return of .the platen to its horizontal position has begun, so that shortly after, the return movement has begun, the grip- .pers are-at their maximum angle of divergence .withrespect to the face ofthe platen. This early recession ofv the grippers from the platen has not been found to .be particularly objectionable inpresses operating .at -.-rel-atively low speeds or when printing on stock ofsubstantial thickness.

, ,I have found, however, in the operation of v presses .athigh speeds, that the sheets were likely to be blown' oil the platen on the up-stroke of the latter, and that in working with very thin stock, that the sheets were likely to .curlduring theup-stroke of the platen, rendering the removal of the sheets therefrom extremely difficult.

.The present invention accordingly has as its primary object the elimination of the .aforesaid difiiculties incidental to the operation of the platen presses. More specifically, it is the object of the inventionto provide mechanism for delaying the, opening or recessive movement of the grippers of platen presses during the up- 7 stroke or return of the platen to sheet-receiving position. Another object of the invention is to form (not shown) of the press.

provide mechanism of the character :set forth which may be driven by the press-operating mechanism. A further object of the invention-is to provide mechanism of the character 'set forth which is independent of the platen or platen 1:5 oscillating mechanism and'which therefore may be adjusted without referencev to the positionof the platen or the platen actuating mechanism.

' To the accomplishment of the foregoing rand.

related ends, said invention, then, consists of :the 1-0 means hereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following .description' setting forth in detail certain mechanism embodying the invention, such disclosed means constituting, 1:5 however, but a few of the, various mechanical forms in which the principle ofthe invention may be utilized.

In said annexed drawings:- I

Fig. 1 is 'a fragmentary elevation of the left side of a platen printing press 'embodying one form of the gripper-operating mechanism; f

Fig. 2 is an enlarged view of theg'ripper-ioper- 'ating mechanism of Fig. 1, with the platen in substantially the form-contacting position;

Fig. 3 is 'a view similar to Fig. 2, but showing in dotted lines the position of the parts immediately preceding the arrival of the platen at the sheetreceiving position, and in-solid lines, the position of the parts when the platen is in sheet-receiving v v upon which is oscillata'hl-y mounted the platen .2, fo'scillation of the platen being effected in the 'usual manner by the cam 3, which is mounted on the large driven gear 4 of the press. The gear 4 is disposed at the right sidenof the press and drivesthe gear 5 at the left side of the 'p're'ssp45 the-gear 5 I serving also as a head, by means-of which the crankrod 6 is driven to oscillate the The gear--15 drives pinion "I, which in turn drives gear :8 mounted on the feeder cam shaft 9 of the press. Shaft 9 has mounted thereon a cam 2H1 which "forms the actuating means for the mechanism now to be described.

The platen 2 has/mounted thereon adjacentits lower :edge brackets l I which form .a pivotazlasupport for the gripper bar l2 upon which the grippers I3 are adjustably mounted. The bar I2 is provided with an integral lug or arm M, the other end of which is pivotally secured-to a link l5 having an elongated opening I 6 in one end. Link I5 is connected to one arm l8 of a bell crank I 1, as by means of a pin I9 extending through the opening 5. The ,pin I 9 formsa pivotal connection between the bell 'crank and the link l5 which is normally maintained by means of a tension spring 20 which intercone nects link l5 and arm l8. The opening Hi, how ever, permits the grippers to be manually deQ-y pressed when adjusting the same withreference to a sheet on the platen. The bell crank-l1 is pivotally mounted on a shaft 2| supported by the throw-off lever bracket 22 mounted on the frame I of the press. crank is provided at its lower end with a roller 24 which is always maintained in contact with the cam'lil as by means of a compression spring 25. One end of the spring .25 is in engagement with a fixed abutment 26 mounted on the frame of the press.

The operation of the aforesaid'mechanism may be briefly described as follows; With the platen 2 in the cam. During the movement of the platen fromthe dotted-line position to the solid line or sheet-receiving position, the bell crank I1 is suddenly moved in a clockwise direction-by engagement of the shoulder Inc of the cam with the roller 24. V This results in a sudden movement of .the grippers l3 away from the platen, so as'to I permitremovalof the printed sheet and the placing of the next sheet on the platen. On the down-stroke of the platen, the grippers remain at. subsequently the same inclination, but the platen is gradually moved to a substantially vertical position so that when it is in the form-contacting position the grippers are again in en gagement with the platen. It will be apparent from the foregoing description that the, delay in the opening movement of the grippers will be effective to prevent the sheets from being blown off the platen on the up-stroke of the platen,and that thin sheets which would otherwise have a tenden'cy'to curl up will be prevented from curling.

In that form of the invention shown in-Figs. 4

surface of the small crank-rod driving head (not .tween the sheeterecelving andprinting position,

. grippers mounted for pivotal movement with r'e- 'spect to said platen and adapted to engage a sheet shown) of the press. 7 v,

The gripper-operating mechanism in this case comprises a link 3| which corresponds with the- 'link l5gin the previouslydescribed form of the invention except that His not provided with an "elongated opening at one end; Link 3| is pivotally connected with a lever 32 as by means of a pin 33, which forms a support for a roller34, said 35. The lever 32 is pivotally mounted on the frame I' of the press, as by means of a pin or stub The other-arm 23 of the bell position. I 2. In a platen to be manually depressed when adjusting the same with respect to a sheet on the platen, thereby dispensing with the necessity for the elongated opening in link 3|.

The operation of the aforesaid mechanism is as follows: With the platen 2 in substantially the form-contacting position as shown in Fig. 4, the v grippers 13 will begin engagement with the sheet on the platen. As' the platen rises to-the dotted line position shown in Fig. 5, the grippers are maintained in engagement with the platen by "virtue of the fact that the roller 34, due to the influence of spring 35, rides up the inclined por-- tion 30a of the cam, thus forcing the link 3| to the'left. Whenthe platen is in the dotted-line position, the roller 34 lies at the top 30b of the protuberance on the cam. During the movement of the platen from the dotted-line position to the solid line or sheet-receiving position the lever is suddenly moved in a clockwise direction as the result of the roller 34 riding down the inclined portion 300 of the cam. This results in a'sudden movement of the grippers I3 away from (the platen, so as to permit removal of theprinted sheets and the placing of the next sheet on the platen. On the down stroke of the platen, the grippers remain at substantially thev same in clination, but the platen is gradually moved to its substantially vertical position, so that when'it is inthe form-contacting position, the grippers are again in engagement with the platen.

Instead of having the grippers open durin'gthe up-stroke ofthe platen, it is possible, by'a "slight variation of thecontour or position' of the cams H1 and 30, to delay the opening of the grippers until the platen has reached the end of its' upstroke or, in fact, to delay such opening until immediately after the platen has reached the end independent of the oscillation of ,the'platen or platen oscillating mechanism and that it may therefore be adjusted without reference to the position of the platen or the platen actuating invention in that it enables the movements of "the grippers to be controlled on both the up and down stroke of the platen in any desired manner. j g

Other modes of applying the principle of'my invention may be employed instead of thoseexplained, change being made ,as regards the mechanism herein disclosed, provided'the means stated by any of the following claims" or the equivalent of sucl'istated means be employed.

, I therefore particularly point out and distinctly claim as my invention: r 1. In a platen printing press, the combination of a platen, means for oscillating said .platen'beon the platen when the latter is in printing posi- I tion, and means for maintaining said grippers in; engagement with said sheet until .the platen has returned to substantially the sheet rec'eiving printing press, the combination of a platen oscillatable between a sheetreceiving and a printing position, grippers angularly movable with respect to said platen, and means for.

, mechanism This is an important feature of the shaft'36. The spring 35 permits the grippersl3 maintaining said grippers substantially parallel with the platen during the major portion of the movement of the platen from the printing to the sheet-receiving position.

3. In a platen printing press, the combination of a platen oscillatable between a sheet-receiving and a printing position, grippers angularly movable with respect to said platen, means for maintaining said grippers parallel with the platen during the major portion of the movement of the platen from the printing to the sheet-receiving position, and means for thereafter moving said grippers away from said platen.

4. In a platen printing press, the combination of a platen oscillatable between a sheet-receiving and a printing position, grippers mounted for pivotal movement towards and away from said platen, means for maintaining said grippers in contact with a sheet on said platen during movement of the platen from the printing to the sheetreceiving position, and means for suddenly moving said grippers away from said platen in the last stages of said movement.

5. In a platen printing press, the combination of a platen oscillatable between a sheet-receiving and a printing posltion, grippers mounted for pivotal movement toward and away from said platen, and cam and lever means for maintaining said grippers in contact with a sheet on said platen during the major portion of the movement of the platen from the printing to the sheetreceiving position.

6. In a platen printing press, the combination of a platen, means for oscillating said platen between the sheet-receiving and printing positions, grippers mounted for pivotal movement with respect to said platen and adapted to engage a sheet on the platen when the latter is in printing position, and means independent of the oscillation of the platen or platen oscillating means for maintaining said grippers in engagement with said sheet until the platen has returned to substantially the sheet-receiving position.

, '7. In a platen printing press, the combination of a platen oscillatable between a sheet-receiving and a printing position, grippers angularly movable with respect to said platen, and means in-' dependent of the oscillation of the platen for maintaining said grippers substantially parallel with the platen during the major portion of the movement of the platen from the printing to the sheet-receiving position.

8. In a platen printing press, the combination of a platen, means for oscillating said platen between the sheet-receiving and printing position, grippers mounted for pivotal movement with respect to said platen and adapted to engage a, sheet on the platen when the latter is in printing position, and means for maintaining said grippers in engagement with said sheet during the major portion of the movement of the platen from the printing to the sheet-receiving position and for thereafter moving said grippers away from saidplaten, said last-named means comprising a cam and a member pivotally mountedv on the frame of said press and movable about cam.

9. In a platen printing press, the combination of a platen, means for oscillating said platen between the sheet-receiving and printing position, grippers mounted for pivotal movement with respect to said platen and adapted to engage a sheet on the platen when the latter is in printing position, and means for maintaining said grippers in engagement with said sheet during the major portion of the movement of the platen from the print- 1 ing to the sheet-receiving position and for thereafter moving said grippers away from said platen, said last-named means comprising a cam, a member pivotally mounted on the frame of said press and a spring biasing said member towards said cam.

its pivot by said,

10. In a platen printing press, the combination 7 of a platen, means for oscillating said platen between the sheet-receiving and printing position, grippers mounted for pivotal movement with respect to said platen and. adapted to engage a sheet on the platen whenthe latter is in printing position, and means for maintaining said grippers in engagement wth said sheet during the major portion of the movement of the platen from the printing to the sheet-receiving position and for thereafter moving said grippers away from said platen, said last-named means comprising a cam mounted on the shaft upon which the platen oscillating means is mounted, a member pivotally mounted on the frame of said press and a spring biasing said member towards said cam.

LAWRENCE R. JOHNSON. 

